Spatial evaluation of land-use dynamics in gold mining area using remote sensing and GIS technology

摘要

Gold mining operations generate a range of ecological and environmental impacts that can be measured spatially using geographic information system and remote sensing methods. This study assessed land-use and land-cover dynamics in the gold mining area using geographic information system and remote sensing techniques with the aid of Landsat 5 for years 1984, 1994, 2004 and Landsat 8 for 2014 and 2019 obtained from the United States Geological Survey and Remote Pixel Databases using ArcGIS 10.4 and R programming. The result from the study revealed the current changes and how they have evolved over the years where tailings dam and built-up areas increased from 90.5 to 172.9 km(2) between the year 1984 and 2019, while mine effluent (return water ponds) and water bodies increased from 14.7 to 18.8 km(2) during the same period. The area also experienced increased vegetation from 342.5 to 371.1 km(2) (though fluctuating during the study period) an indication that the area has witnessed revegetation in the area. Results from the study further revealed the vegetation health in the area utilises some vegetation indices such as the Global Environmental Monitoring Index, Normalised Difference Impervious Surface Index and Normalised Difference Moisture Index. Findings from the study show that areas with low index values are susceptible to the impact of mining and other anthropogenic activities, whereas high-index areas connote little or no impact. The outcome of this study provides a cost-effective tool for evaluating environmental impacts in mining areas that can drive policy interventions for remediation in affected areas.